Ettore Bugatti is famous for his luxury sports cars. But he also designed aero engines and the aircraft to go with them. His most advanced design was the Bugatti 100 P, a racing aircraft designed to beat the world speed record. It was ready in 1940, but could not be tested before the German invasion. Miraculously, the prototype survived WWII hidden in a barn. It is now in a museum in the USA.
The French Air Force was impressed by the expected performance and ordered a fighter version, the Bugatti 110 P, which was never built.
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